As can be seen from the other messages from obviously very experienced ribbers, don't beat yourself up. We all learn by experience! It is virtually the only way, and as many say, any other boater will help you given half a chance, it is a close community due to the dangers involved. No one hurt, except "his" pride of being sick!
Keep going, if you never try you will never know. Live fast die young. You only live once. Many phrases are cheesy but they all stem from the truth.
You will look back with strong memories of the day and that is all part of boating. The most uncomfortable experiences and worrying times not only teach you the most, but provide the best stories to recount in the pub!!
Good luck going forward and don't worry, you are fairly prepared as far as i can see from your posts. It is the idiots who go out with no lifejackets and no fuel that get given grief!